Degradation pathways of holocellulose, lignin and a-cellulose from Pteris vittata fronds in sub- and super critical conditions Marion Carrier a, *, Anne Loppinet-Serani a , Christelle Absalon b , Cyril Aymonier a , Michel Mench c a CNRS, Universite ´ de Bordeaux, ICMCB, IPB-ENSCBP, 87 avenue du Dr. A. Schweitzer, FR-33608 Pessac Cedex, France b Universite ´ de Bordeaux, ISM-CESAMO, 351 cours de la Libe ´ration, 33405 Talence Cedex, France c UMR BIOGECO INRA 1202, Ecologie des communaute ´s, Universite ´ Bordeaux 1, Bat B2 RdC Est, Avenue des Faculte ´s, FR-33405 Talence, France article info Article history: Received 18 October 2011 Received in revised form 28 March 2012 Accepted 30 March 2012 Available online Keywords: Subcritical water treatment Supercritical water treatment Holocellulose a-cellulose Lignin abstract Fern (Pteris vittata L.) fronds were collected in the Reppel small-scale field experiment aiming at arsenic phytoextraction. Three organic fractions, i.e. holocellulose, hemi- celluloses, and lignin, were extracted from the fronds. The frond biomass as well as the holocellulose, hemicelluloses, and lignin fractions were converted by sub- and super critical water treatments at low temperatures, 300  C and 400  C with 25 MPa, and organic products were identified. This study highlighted that hemicelluloses and lignin are reported as the major sources of cyclopentenones and furfurals, 5 carbons-containing products. The degradation of carbohydrates part (holocellulose and a-cellulose) provided the largest range of by-products due to the thermal resistance of the lignin. The control of biochemical families’s content and temperature should determine the presence of required by-products. The fact that no ‘synthetic’ materials but original materials, i.e. holocellulose, a-cellulose and lignin directly extracted from control fern fronds have been converted revealed the presence of benzenes and cyclopentenones, by-products which have not been reported by the literature. ª 2012 Elsevier Ltd. All rights reserved. 1. Introduction The conversion of uncontaminated and As-contaminated fronds of Pteris vittata L. by sub- and super critical water treatments has showed the production of various organic compounds in the liquid phases [1]. The comparison of organic compounds of the liquid phases produced during the sub- and super critical water treatments of fronds showed the presence of various organics (Cyclopentanones, cyclo- pentenol, furfurals, benzene, diols, guaı ¨acols and phenols) identified by GCeMS [1]. One major question is from which plant fraction(s) derived the organic compounds in the liquid phases when fern fronds are converted by sub- and super critical treatments? The degradation pathways of plant biomasses through sub- and super critical water treatments have been already summa- rized in a previous work [1]. The liquefaction and/or gasifica- tion of the main component, i.e. cellulose, were investigated by Kruse et al. [2] and the main reaction pathways were gathered by Lu et al. [3]. They showed two parallel paths of conversion. The glucose can be decomposed into acids/alde- hydes through free radical reactions (T > 374  C), while it is * Corresponding author. E-mail addresses: marion_carrier@msn.com, carrier@sun.ac.za (M. Carrier). Available online at www.sciencedirect.com http://www.elsevier.com/locate/biombioe biomass and bioenergy 43 (2012) 65 e71 0961-9534/$ e see front matter ª 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.biombioe.2012.03.035